Author
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Reeves Iii, James |
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Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/16/2001 Publication Date: 5/16/2001 Citation: N/A Interpretive Summary: Spectroscopy uses the interaction between light and various materials to determine the composition of the material in question. Near-infrared diffuse reflectance spectroscopy (NIRS) uses the reflection of light beyond the range of human vision and has been used to determine the composition of animal feeds, human foods and other materials. The objective of this research was to evaluate near-infrared diffuse reflectance spectroscopy for determining the composition of poultry manures. Poultry manure samples were obtained from a commercial testing laboratory along with conventionally determined analyte values for total-nitrogen, ammonium-nitrogen, organic-nitrogen (computed as total minus ammonium-nitrogen), minerals and moisture. Samples were blended in a food blender, and scanned in polyethylene bags on a FOSS- NIRSystems model 6500 scanning near-infrared spectrometer. Initial results indicated that changes had occurred in ammonium- nitrogen contents from the time of analysis and samples were re- analyzed for ammonium-nitrogen. Using the new analyses, NIRS was able to accurately determine ammonium-, organic- and total- nitrogen, and moisture in 128 poultry manures. Results were more accurate when determinations were made on an "as is" or non-dried basis as opposed to on a dried basis. Finally, results indicated that NIRS was not suitable for the determination of minerals (calcium, phosphorus, potassium, etc.) in poultry manures. Technical Abstract: The objective of this research was to evaluate near-infrared diffuse reflectance spectroscopy (NIRS) for determining the composition of poultry manures. Poultry manure samples were obtained from a commercial testing laboratory along with conventionally determined analyte values for total-N, NH4+-N, organic-N (computed as total minus NH4+-N), minerals and moisture. Samples were blended in a food blender, and scanned in polyethylene bags on a FOSS-NIRSystems model 6500 scanning monochromator. Initial results indicated that changes had occurred in NH4+-N contents from the time of analysis and samples were re-analyzed for NH4+-N. Using the new analyses, NIRS was able to accurately determine NH4+-N, organic-N, total-N, and moisture in 128 poultry manures. Results were more accurate when determinations were made on an "as is" as opposed to dry matter basis. Finally, results indicated that NIRS was not suitable for the determination of minerals (P, K, Ca, etc.) in poultry manures. |
